Root-knot nematodes

scouted July 21, 2026

Scientific Name
Meloidogyne sp.
Background
A tobacco field, variety GL365, in Alamance County was being scouted, and it was observed that 10% of the field was affected by browning, yellowing, malformation, stem rot, stunting, and wilting in a localized area. The site is dry but received a good amount of rain. Disease was specific to this variety, but not the other varieties found in the field. A sample was submitted to the PDIC for diagnosis.
Conclusion
The issue was identified as Root-knot Nematodes (Meloidogyne spp.), which are microscopic roundworms that affect a wide range of plant hosts, including tobacco. These nematodes complete their life cycle in the soil and roots, where juveniles infect roots and establish feeding sites that cause characteristic galling. Aboveground symptoms often appear in patches across the field and include chlorosis, stunting, and wilting. Symptoms are frequently more severe under drought conditions due to reduced water and nutrient uptake and increased susceptibility to secondary root pathogens.Management of root-knot nematodes is challenging because of their broad host range, and effective control relies on integrated management practices, including routine soil sampling to assess nematode presence and population levels.

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